chapter 7 notes

Chapter 7: Nervous System

Part 2: Central Nervous System

A.    Development

a.    Embryonic neural tube-CNS develops from the embryonic neural tube, the neural tube becomes the brain and spinal cord, the opening of the hollow neural tube becomes the ventricles: four chambers within the brain, filled with cerebrospinal fluid.

b.    Ventricles

B.    Regions of the brain

a.    Cerebral hemispheres (cerebrum)

                                          i.    Paired-(left and right) superior parts of the brain.

                                        ii.    Mass-Includes more than half of the brain mass.

                                       iii.    Surface-Surface is made of ridges(gyri) and grooves(sulci).

1.     Gyri-Ridges

2.    Sulci-Grooves

                                       iv.    Lobes

1.     Fissures-Deep grooves, divide the cerebrum into lobes.

2.    Surface lobes- named for adjacent bones.

a.    Frontal

b.    Parietal

c.    Occipital

d.    Temporal

                                         v.    Specialized areas of cerebrum

1.     Primary somatic sensory-Receives impulses from the body’s sensory receptors, located in parietal lobe.

2.    Primary motor-Sends impulses to skeletal muscles, located in frontal lobe.

3.    Broca’s-Involved in our ability to speak.

4.    Special senses

a.    Gustatory-Taste

b.    Visual

c.    Auditory-Hearing

d.    Olfactory-Smell

5.    Interpretation areas

                                       vi.    Layers

1.     Gray matter-Outer layer in the cerebral cortex composed mostly of neuron cell bodies.

2.    White matter-Fiber tracts deep to the gray matter.

a.    Corpus callosum-Connects hemispheres.

3.    Basal nuclei-Islands of gray matter buried within the white matter.

b.    Diencephalon

                                          i.    Location-On top of brain stem, enclosed by the cerebral hemispheres.

                                        ii.    Made of three parts

1.     Thalamus- Hypothalamus, Epithalamus.

a.    Location-Surrounds the third ventricle.

b.    Functions-The relay station for sensory impulses, transfers impulses to the correct part of the cortex for localization and interpretation.

2.    Hypothalamus

a.    Location-Under the thalamus.

b.    Functions: autonomic nervous system center

c.    Pituitary gland: master gland of endocrine system

d.    Controls water balance, regulates metabolism.

e.    Controls emotions.

3.    Epithalamus

a.    Location-On top of the thalamus.

b.    Functions-Forms the roof of the third ventricle, houses the pineal body( an endocrine gland).

c.    Brain stem

                                          i.    Location-Attaches to the spinal cord.

                                        ii.    Parts

1.     Midbrain

2.    Pons

3.    Medulla oblongata

a.    Control centers-Heart rate, blood pressure, breathing.

4.    Reticular formation

a.    Reticular activating system (RAS)

d.    Cerebellum-Two hemispheres with convoluted surfaces, provides involuntary coordination of body movements.